This invention relates generally to digital imaging devices and particularly to the use of complementary metal oxide semiconductor (CMOS) photosensitive elements.
Digital imaging devices commonly utilize charge coupled device (CCD) imagers or complementary metal oxide semiconductor (CMOS) imaging arrays. CMOS imaging arrays, while currently having lower resolution than the CCD arrays, have the advantage that they may be formed by conventional integrated circuit manufacturing processes. As a result, they may be integrated with logic and memory which may enable the devices to not only capture an image but also to analyze and operate on the captured image all in one integrated circuit. This may result in a more compact design at lower cost.
Generally CMOS imaging arrays are utilized in digital cameras. The digital cameras may take a relatively high resolution picture and this picture may be transferred and stored in a tethered computer system.
CCD based cameras are also very popular. In addition CCD-based sensors are also used in various close-up applications such as fingerprint identification. In fingerprint identification, an image of the user's fingerprint is taken. That image may be stored in a database or it may be used for user identification. That is, the image of the user's fingerprint may be compared to a stored list of authorized users. Once the user is identified by his or her fingerprint, the user may be allowed access to a computer system or otherwise allowed access to a limited access control point.
Similarly, text readers may be utilized to image a text array and either store the text information for later analysis or magnify the text for viewing by those having limited vision. Conventionally, the imaged text is analyzed and stored in separate integrated circuit chips because conventionally CCD sensors are utilized.
There is a continuing need for lower cost or more compact imaging devices for close-up imaging applications.